JPH05217239A - Recording and reproducing device for magneto-optical disk - Google Patents

Abstract

PURPOSE:To simplify the mechanical part of a device, to miniaturize the device itself and to record the information signal of a large capacity by using a magneto-optical disk with a small diameter. CONSTITUTION:The magneto-optical 102 constituted of a disk substrate whose thickness is 1.2mm or below and whose diameter is 95mm or below, a disk rotation driving means 3, 4, an optical head means 18, an external magnetic field generation means 66 and a control means 1 are housed in a housing body 1 and integrated into one body whose width is 101.6mm or below and whose depth is 145mm or below and whose height is 25.4mm or below.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magneto-optical disk recording / reproducing apparatus using a magneto-optical disk as a recording medium for information signals.

[0002]

2. Description of the Related Art Conventionally, a disk cartridge that rotatably houses a magneto-optical disk is mounted in a state where the magneto-optical disk is housed, and an information signal is recorded on the magneto-optical disk, or the magneto-optical disk is recorded. A magneto-optical disk recording / reproducing apparatus has been proposed which reproduces an information signal recorded on a disk.

This magneto-optical disk recording / reproducing apparatus has a loading mechanism for loading a disk cartridge accommodating a magneto-optical disk to a cartridge mounting position in the apparatus, and a magneto-optical disk housed in a disk cartridge mounted at the cartridge mounting position. An information signal is recorded on a disk rotation drive mechanism that holds a disk and drives it to rotate, and a magneto-optical disk that is rotationally driven by this disk rotation drive mechanism, or reproduces an information signal recorded on this magneto-optical disk. An external magnetic field that applies a vertical magnetic field to the magneto-optical disk when an information signal is recorded on the magneto-optical disk and is arranged to face the optical head apparatus with the magneto-optical disk interposed therebetween. And a device.

The loading mechanism for loading the disk cartridge has a cartridge holder arranged to hold the disk cartridge inserted in the apparatus main body in a state parallel to the bottom surface of the apparatus main body. Is configured to be moved up and down in the apparatus main body by using a cam mechanism or the like. This loading mechanism moves the disk cartridge held by the cartridge holder in a direction parallel to the main body of the device, which is a direction along the main surface of the magneto-optical disk, and the center of the magneto-optical disk housed in the disk cartridge and the disk. When the rotation center of the rotation drive mechanism reaches a position where the rotation centers substantially coincide with each other, the disc cartridge is lowered toward the disc rotation drive device. When the disc cartridge is lowered in this manner, the magneto-optical disc housed in the disc cartridge is held on the disc table of the disc rotation drive device.

Further, the optical head device is arranged in the main body of the device so as to face the signal recording surface formed on the main surface of the magneto-optical disk which is rotated by the disk rotation drive mechanism. The optical head device is supported over the inner and outer circumferences of the magneto-optical disk so as to be movable in the radial direction of the disk. This optical head device irradiates a light beam over substantially the entire area of the signal recording surface of the magneto-optical disk by being moved in the radial direction of the magneto-optical disk that is rotationally driven by the disk rotation drive mechanism. This makes it possible to record or reproduce an information signal on almost the entire area of the signal recording surface of the magneto-optical disk.

Further, the optical head device has a focus servo and a tracking servo for causing a light beam irradiating the disk to follow so-called surface wobbling and eccentricity due to the rotation of the magneto-optical disk which is rotationally driven by the disk rotation drive mechanism. It has an objective lens drive mechanism for performing. This objective lens driving mechanism uses an objective lens for converging a light beam on a signal recording surface of a magneto-optical disk by a supporting member made of, for example, an elastically displaceable leaf spring, in the optical axis direction of the objective lens and in the optical axis direction. It is movably supported in two directions perpendicular to the optical axis and is driven and displaced by the electromagnetic driving means in the optical axis direction of the objective lens or in the direction orthogonal to the optical axis direction.

The electromagnetic driving means for driving and displacing the objective lens is attached to a lens bobbin which is supported by a supporting member and holds the objective lens, and is based on a focus error signal or a tracking error signal for performing focus servo or tracking servo. A drive coil to which a drive current is supplied, and a magnetic circuit section which, together with the current flowing through the drive coil, generate a drive force for displacing the objective lens in the optical axis direction and a direction orthogonal to the optical axis direction are provided.

Further, the external magnetic field generator, which is arranged in the main body of the apparatus so as to face the optical head device with the magneto-optical disk interposed therebetween, is brought close to the magneto-optical disk when recording an information signal on the magneto-optical disk. A vertical magnetic field is applied to the magneto-optical disk.

[0009]

By the way, as described above, the disc cartridge inserted into the main body of the apparatus is moved horizontally with respect to the main body of the apparatus and then moved vertically to be housed in the disc cartridge. In a magneto-optical disk recording / reproducing apparatus equipped with a loading mechanism adapted to mount and hold a magneto-optical disk on a disk rotation drive mechanism, the structure of the loading mechanism becomes complicated,
It is extremely difficult to reduce the size of the device itself by simplifying the mechanism portion provided in the device body, and there is a problem that the assembly becomes extremely complicated.

Further, in a magneto-optical disk recording / reproducing apparatus in which the magneto-optical disk is mounted in the disk cartridge as it is, it is necessary to make the main body of the apparatus large enough to house the disk cartridge. Yes,
The external shape of the apparatus body cannot be made smaller than the size of the magneto-optical disk to be mounted.

Further, the optical head device constituting the above-mentioned magnetic disk recording / reproducing apparatus includes an optical block including a light source for emitting a light beam, an objective lens for converging the light beam on the magneto-optical disk and irradiating the same, and this objective. Since the objective lens driving device such as the objective lens driving mechanism for driving and displacing the lens is integrally formed, not only the size is increased but also the weight is increased. Therefore, the drive means for moving and operating the optical head device and the mechanism for supporting the optical head device are increased in size.

In order to reduce the size of the magneto-optical disk recording / reproducing apparatus, it is possible to use a magneto-optical disk having a small diameter as a recording medium. Although it is possible to reduce the size of the device body by using a small-diameter magneto-optical disk, it is not possible to guarantee a sufficient recording capacity of information signals, and a magneto-optical disk recording used for the purpose of a large-capacity information storage device. The usefulness of the playback device is impaired.

Therefore, an object of the present invention is to provide a magneto-optical disk recording / reproducing apparatus capable of recording a large-capacity information signal even when a small-diameter magneto-optical disk is used as a recording medium. ..

Further, an object of the present invention is to realize a magneto-optical disk which simplifies a mechanical portion constituting the recording / reproducing apparatus, realizes miniaturization of the apparatus itself, and facilitates assembling. It is to provide a recording / reproducing apparatus.

A further object of the present invention is to provide a magneto-optical disk recording / reproducing apparatus which allows a large-sized magneto-optical disk to be used in a small apparatus body.

[0016]

In order to achieve the above-mentioned object, the magneto-optical disk recording / reproducing apparatus according to the present invention has a light-transmitting property of 1.2 mm or less and 95 mm or less in diameter. A magneto-optical disk having a signal recording layer formed on one main surface side of a disk substrate having a plurality of signal recording areas and having linear recording densities substantially equal to each other from the inner circumference to the outer circumference, A disk rotation driving means for mounting a magnetic disk and rotating the magneto-optical disk at a constant angular velocity, an optical head means for irradiating the magneto-optical disk with a light beam, and an optical head means for sandwiching the magneto-optical disk. External magnetic field generating means arranged opposite to each other for applying a vertical magnetic field to the magneto-optical disk when recording an information signal on the magneto-optical disk, and the disk rotation driving means. And control means for controlling said optical head means and said external magnetic field generating means, the width of 101.6mm
The magneto-optical disc, wherein the depth is 145 mm or less and the height is 25.4 mm or less.
The disk rotation driving means, the optical head means, the external magnetic field generating means, and the outer casing for housing the control means are provided.

Further, in the magneto-optical disk recording / reproducing apparatus according to the present invention, the above-mentioned optical head means is provided with a fixed optical system portion having at least a light source, a light detecting means and an optical element for detecting a focus error. A movable optical system section that is movable in the radial direction of the magneto-optical disk with respect to the fixed optical system and that includes an objective lens that focuses the light beam from the light source on the signal recording area of the magneto-optical disk. And a feeding means for feeding and operating the movable optical system portion in the radial direction of the magneto-optical disk.

Further, in the magneto-optical disk recording / reproducing apparatus according to the present invention, the movable optical system section is guided in the system direction of the magneto-optical disk by the feeding means for feeding and operating the movable optical system section in the radial direction of the magneto-optical disk. The optical head means is provided with a pair of parallel guide portions and means for movably supporting the movable optical system portion along the pair of parallel guide portions.

Further, in the magneto-optical disk recording / reproducing apparatus according to the present invention, the objective lens for converging the light beam from the light source on the signal recording area of the magneto-optical disk is an aspherical surface having a numerical aperture of 0.55 or less. It is a lens.

Further, in the magneto-optical disk recording / reproducing apparatus according to the present invention, the magneto-optical disk has a storage capacity of 300.
Use at least megabytes.

[0021]

The magneto-optical disk recording / reproducing apparatus according to the present invention comprises:
The magneto-optical disk, disk rotation driving means, optical head means, external magnetic field generating means and control means have a width of 101.6.
It is housed and integrated in an outer casing which has a depth of 145 mm or less and a height of 25.4 mm or less.

The information signal is recorded on a magneto-optical disk constructed by using a disk substrate having a thickness of 1.2 mm or less and a diameter of 95 mm or less housed in the outer casing.

Further, when recording / reproducing information signals to / from the magneto-optical disk, only the movable optical system portion of the optical head means is fed and operated in the radial direction of the magneto-optical disk.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, a magneto-optical disc recording / reproducing apparatus according to the present invention has an outer casing 1 which constitutes a main body of the device, and a magneto-optical disc 102 in which a desired information signal is recorded in the outer casing 1. Is built in.

Magneto-optical disk 1 used in the apparatus of the present invention
As shown in FIGS. 6 and 7, reference numeral 02 denotes a signal recording layer 111 on one main surface side of a disk substrate 110 having a disk shape made of a synthetic resin material such as transparent polyataseur resin having a light transmitting property or a glass material. The magnetic material constituting the above is adhered and formed, and the protective film 112 made of synthetic resin is adhered and formed so as to cover the signal recording layer 111.

The disc substrate 110 constituting the magneto-optical disc 102 has a thickness d of about 1.2 mm,
It is formed in a disk shape having a diameter r of 86 mm. The magneto-optical disk 102 configured by using this disk substrate 110 has a signal recording layer 11 having a thickness of the disk substrate 110.
1 and the protective film 112 are added, and the diameter R ₁ is formed to be approximately 86 mm corresponding to the outer peripheral diameter of the disk substrate 110. Then, this magneto-optical disk 10
Reference numeral 2 is a signal recording area having a portion where the signal recording layer 111 is formed over the inner and outer peripheries on one main surface side.

Further, as shown in FIGS. 1 and 6, a hub mounting hole 105 is provided at the center of the magneto-optical disk 102. A disk hub 106 for holding the magneto-optical disk 102 on the disk table 23 constituting the disk rotation drive mechanism is installed in the hub mounting hole 105 as described later. The disc hub 106 is formed of a magnetic material such as metal into a substantially disc shape, and is attached to the disc substrate by a method such as adhesion or welding with the center aligned with the center of the magneto-optical disc 102. At the center of the disk hub 106, a center hole 107 is formed whose center coincides with the center of curvature of a recording track spirally formed on the signal recording layer of the magneto-optical disk 102.

The magneto-optical disk 1 constructed as described above.
As shown in FIGS. 1, 2, and 3, the outer casing 1 that constitutes the main body of the device in which 02 is built is formed as a rectangular casing, and the chassis that constitutes the bottom plate of this outer casing 1 on the bottom side. 2 are provided. The upper surface side that faces the bottom surface side on which the chassis 2 is disposed is the upper lid 1 that constitutes the upper surface wall.
0 is removably attached via a screw 11 to be closed. In addition, the opening 1a on the front surface side of the outer casing 1
The front panel 24 is attached and closed.

As shown in FIG. 2, the outer casing 1 has a width Q of 101.6 mm including the front panel 24.
It is formed in a rectangular parallelepiped shape with a depth P of 145 mm or less and a height H of 25.4 mm or less. More specifically, the outer casing 1 has a width Q of 1
It is formed in a rectangular parallelepiped shape having a depth of 01.6 mm, a depth P of 145 mm, and a height H of 18 mm.

By the way, the height H of the outer casing 1 is made as thick as 25.4 mm due to the height of the disk rotation drive mechanism arranged in the outer casing.

On the chassis 2 which constitutes the bottom plate of the outer casing 1, rotation driving means, optical head means, magnetic field generating means and the like are arranged.

That is, on the chassis 2, there is provided a spindle motor 3 which constitutes a disk rotation drive mechanism for rotationally driving the magneto-optical disk 102. The spindle motor 3 is mounted on the chassis 2 while being supported by a ring-shaped support block 6. That is, the spindle motor 3 is supported on the chassis 2 by fitting the housing into the fitting hole portion 9 of the support block 6 so that the spindle shaft 5 integrated with the drive shaft is substantially perpendicular to the chassis 2. ing. At this time, the tip end side of the spindle shaft 5 is projected above the chassis 2.

The spindle shaft 5 of the spindle motor 3 has a disk hub 106 for the magneto-optical disk 102.
The disk table 4 having substantially the same diameter as the disk hub 106 that supports the disk is integrally mounted. The magneto-optical disk 102 is mounted so that a disk hub 106 is supported on the disk table 4 and can rotate in synchronization with the disk table 4. in this way,
The outer diameter of the disk rotation drive mechanism in which the magneto-optical disk 102 is integrally mounted on the disk table 4 is 86 m, which corresponds to the outer diameter of the magneto-optical disk 102 mounted here.
m.

On the chassis 2, an optical pickup device, which is located at the rear side of the spindle motor 3 and comprises an optical block section 18 and an objective lens drive section 17, is provided as an optical head means. This optical pickup device is for irradiating a magneto-optical disk 102 mounted on the disk table 4 with a light beam for recording and / or reproducing an information signal.

As shown in FIG. 4, the optical block portion 18 constituting the optical pickup device guides a plurality of semiconductor lasers 50 as light sources and a plurality of light beams emitted from the semiconductor lasers 50 into a block as a lens barrel. The optical components are stored and arranged. This optical block section 18
Inside, the divergent light beam emitted from the semiconductor laser 50 is incident on the collimator lens 51, and is made into a parallel light beam by the collimator lens 51. The parallel light beam that has passed through the collimator lens 51 passes through the beam splitter prism 52, and then the galvano mirror 53.
Is incident on. The galvano mirror 53 is controlled by the control means described later, and deflects the incident parallel light beam based on a predetermined control signal and reflects it. The parallel light beam reflected by the galvanometer mirror 53 is emitted from the optical block unit 18, and the objective lens driving unit 1
It is incident on 7.

As the semiconductor laser 50 used here, one that emits a light beam having a wavelength of 780 nm is used.

On the other hand, the objective lens driving unit 17 has a frame 17a, and a pair of guide shafts 63 and 64 are mounted in the frame 17a so as to be parallel to each other and to the chassis 2. Between these guide shafts 63, 64, these guide shafts 6
A lens bobbin block 60, which is a movable optical system unit, is arranged so as to be movable in the direction along the chassis 2 while being guided by 3, 64. That is, the lens bobbin block 60 has three guide rollers 61 and 6 attached to both side portions facing the guide shafts 63 and 64, respectively.
1, 61 and 62, 62, 62 are supported by the guide shafts 63, 64 via the guide shafts 6 and 6.
Guided by 3, 64, it is movable in the direction along the chassis 2. Then, the lens bobbin block 60
Guide rollers 61, 61, 61 mounted on one side of the
At least one of which is supported by a support shaft projecting obliquely upward 45 ° from the lens bobbin block 60, and the other is supported by a support shaft projecting obliquely downward 45 ° from the lens bobbin block 60. .. The guide rollers 61, 61, 61 are rollable so as to sandwich the one guide shaft 63. Further, the guide rollers 62, 62, 62 mounted on the other side of the lens bobbin block 60 are the guide rollers 63, 62 on the one side.
Like 63 and 63, at least one is supported by a support shaft projecting obliquely upward 45 ° from the lens bobbin block 60, and the other is obliquely below the lens bobbin block 60.
It is supported by a support shaft protruding in the 5 ° direction. And
These guide rollers 62, 62, 62 are rollable so as to sandwich the other guide shaft 64.

The movable direction of the lens bobbin block 60, that is, the guide shafts 63, 64
The extending direction of the magneto-optical disk 10 is a position closer to the spindle motor 3 as indicated by an arrow L in FIG.
2 is a direction connecting an inner peripheral side position of No. 2 and an outer peripheral side position of the magneto-optical disk 102, which is a position away from the spindle motor 3. Also, the lens bobbin block 60 is
A feed motor 65 provided in the frame 17a of the objective lens driving unit 17 guides the guide shafts 63 and 64 to feed the object. The feed motor 65 is composed of, for example, a linear motor.

An objective lens 55 is attached at a position facing the upper surface of the lens bobbin block 60.
In the lens bobbin block 60, the reflection mirror 5 that reflects the parallel light beam incident from the optical block unit 18 as a fixed optical system unit and makes it incident on the objective lens 55.
4 are provided. That is, the parallel light beam that is incident on the objective lens driving unit 17 from the optical block unit 18 is incident on the objective lens 55 via the reflection mirror 54 to be a focused light beam, and the spindle shaft 5
The signal recording surface of the magneto-optical disk 102 on the disk table 4 is irradiated with the optical axes parallel to each other.

The objective lens 55 used here is an aspherical single lens having a numerical aperture (NA) of 0.55.

Then, the light beam emitted from the objective lens 55 and applied to the magneto-optical disc 102 on the disc table 4, and reflected from the magneto-optical disc 102 is incident on the objective lens 55 again and becomes a parallel light beam. Then, it reaches the reflection mirror 54, is reflected by the reflection mirror 54, and is returned to the optical block portion 18 side. The optical block unit 18 has a built-in photodetector and the like for detecting the light beam reflected from the magneto-optical disk 102. That is, the light beam returned from the objective lens driving unit 17 to the optical block unit 18 returns to the beam splitter prism 52 via the galvano mirror 53. The beam splitter prism 52 allows the light beam returned from the galvano mirror 53 to enter the Wollaston prism 56 without returning to the collimator lens 51 side. The Wollaston prism 56 is formed by joining two right-angle prisms made of a material having optical anisotropy, such as calcite and quartz, so that their optical axes are orthogonal to each other. The light beam incident on the Wollaston prism 56 is separated into two linearly polarized lights having vibration planes orthogonal to each other. The light beam transmitted through the Wollaston prism 56 is transmitted through a condensing lens 57 composed of a convex lens and a multi-lens 58 in which one surface is a concave surface and the other surface is a cylindrical surface (cylindrical surface). The light is received by a photodetector 59 such as a photodiode.

Then, according to the light detection output obtained based on the returning light beam from the magneto-optical disk 102 received by the photodetector 59, the condensing point of the light beam focused by the objective lens 55 and the light A focus error signal indicating the amount of displacement of the objective lens 55 in the optical axis direction, which is the positional displacement from the signal recording surface of the magnetic disk 102, the recording point formed on the signal recording surface of the magneto-optical disk 102, and the focus point of the light beam. A tracking error signal indicating the amount of displacement of the objective lens 55 in the direction orthogonal to the optical axis, which is the positional displacement with respect to the track, and the reproduction of the information signal obtained by reading the information signal recorded on the recording track of the magneto-optical disk 102. The signal is obtained.

Further, as shown in FIGS. 1 and 5, the lens bobbin block 60 has a magnetic head device 6 which constitutes an external magnetic field generating means via a magnetic head supporting arm 19.
6 is attached. The magnetic head device 66 is for applying a vertical magnetic field modulated according to the information signal to be recorded, when the information signal is recorded on the magneto-optical disk 102. The magnetic head support arm 19 that supports the magnetic head device 66 is supported by the lens bobbin block 60 on the base end side so as to be movable in synchronization with the lens bobbin block 60. Further, the magnetic head support arm 19 is formed so that the magnetic head device 66 supported on the tip side faces the objective lens 55 of the lens bobbin block 60 with the magneto-optical disk 102 interposed therebetween. That is, the magnetic head support arm 19 is
The tip side is extended so as to face the objective lens 55 through a substantially U-shaped bend provided in the middle part. The magnetic head device 66 and the objective lens 55, which are opposed to each other with the magneto-optical disk 102 sandwiched therebetween, form the magneto-optical disk 1 described above.
No. 02, the working distance of the objective lens 55, and the amount of surface wobbling that occurs when the magneto-optical disk 102 is rotationally driven by the disk rotational driving mechanism, are opposed to each other. The working distance of the objective lens 55 is the distance from the tip of the objective lens 55 to the focal point of the objective lens 55.

The magneto-optical disk recording / reproducing apparatus according to the present invention, based on various control signals inputted,
A control device 70 configured as shown in FIG. 10 for controlling the operations of the optical pickup device including the spindle motor 3, the lens bobbin block 60, the magnetic head device 66, and the like.
Is provided. As shown in FIG. 1, the control device 70 is configured by mounting predetermined electronic circuit components on a printed circuit board 12 arranged on an inner surface of an upper lid 10 that constitutes an upper wall of the outer casing 1. Become.

The control device 70 receives an operation signal input from the outside of the magneto-optical disk recording / reproducing device via an input device manually operated, a signal output from the optical pickup device, and the spindle motor 3. Also, a detection signal and the like obtained by detecting the rotation speed and the rotation angle position of the lifting motor 11 are input. Therefore, in this magneto-optical disk recording / reproducing apparatus, the tracking servo operation by driving the galvano mirror 53 arranged in the optical block 18 constituting the optical pickup device,
As will be described later, the focus servo operation and the spindle servo operation for keeping the rotation speed of the spindle motor 3 constant by controlling the drive of the lifting motor 11 are performed based on a control signal from the control device 70.

Further, the feed motor 65 makes the lens bobbin block 6 based on the detection output from the optical pickup device.
0 is sent in the radial direction of the magneto-optical disk 102, and the objective lens driving unit 17 is driven by an access command from an external device, for example, a control device 70 operated based on a command from a host computer, via an input / output controller 74 described later. Is sent to a desired position on the magneto-optical disk 102.

In this magneto-optical disc recording / reproducing apparatus, the pickup 70 is controlled by the control device 70 so that the output level of the semiconductor laser 50 becomes the reproducing level, so that the magneto-optical disc 102 is recorded. The reading of the information signal is performed by the optical pickup device. The information signal recorded on the magneto-optical disk 102 read by the optical pickup device is modulated and demodulated by the control device 70.
And is demodulated. This modulation / demodulation circuit 72a
The information signal demodulated by is stored in the memory device 73 controlled by the control device 70. This memory device 7
The signal stored in No. 3 is output to various external devices via the input / output controller 74 controlled by the control device 70. The signal stored in the memory device 73 is
The data is output to various other external devices via the decoder 75 controlled by the control device 70, and further D /
The analog audio signal is output to various external devices via the A converter 76.

In this magneto-optical disk recording / reproducing apparatus, information signals input from various external devices are
It is stored in the memory device 73 via the input / output controller 74. The signal stored in the memory device 73 is sent to the magnetic field modulation circuit 72b for modulation processing. The signal modulated by the magnetic field modulation circuit 72b is supplied to the drive circuit 77 of the magnetic head device 66, and at the same time, the control device 70.
Thus, the drive circuit 71 of the semiconductor laser 50 is controlled to set the output level of the semiconductor laser 50 of the optical pickup device to the recording level. Then, a desired information signal is recorded in the signal recording area of the magneto-optical disk 102 by the optical pickup device and the magnetic head device 66.

External equipment to which an information signal or the like output from the magneto-optical disc recording / reproducing apparatus or an information signal to be recorded on the magneto-optical disc 102 is supplied is an external device of the outer casing 1 as shown in FIG. It is connected to a connection connector 13 arranged on the rear wall 1b side via a connection cord.

In the magneto-optical disk recording / reproducing apparatus according to the present invention having the above-mentioned structure, the spindle motor 3
When is driven, the magneto-optical disc 102 mounted on the disc table 4 is rotationally driven at a constant angular velocity in synchronization with the disc table 4. The optical block section 18 and the lens bobbin block section 17 are also provided.
The optical pickup device and the magnetic head device 66, which record information signals, record an information signal by irradiating the magneto-optical disk 102 rotated by the spindle motor 3 with a light beam and applying a vertical magnetic field. Further, by irradiating the magneto-optical disk 102 with a light beam without applying a vertical magnetic field from the magnetic head device 66, the magneto-optical disk 10 is produced.
The information signal already recorded in 2 is reproduced.

By the way, the signal recording area formed on one main surface side of the magneto-optical disk 102 used in the apparatus of the present invention is divided into a plurality of areas (ZONE) as shown in FIG. That is, the innermost area of the signal recording area is the first zone A. A second zone B is formed on the outer peripheral side of the first zone A so as to surround the first zone A, and a second zone B is formed on the outer peripheral side of the second zone B so as to surround the second zone B. 3 zones C are formed, and the third zone C is provided on the outer peripheral side.
The fourth zone D is configured so as to surround the zone C of 1. In each of these zones A, B, C and D, as shown in FIG. 8, a digitalized information signal is written in a so-called pit shape. The pits corresponding to these information signals are fine projections, holes, or perforations formed on one main surface of the disk substrate forming the magneto-optical disk 102, or the disk substrate of the magneto-optical disk 102. It is formed by the difference in the magnetization direction in the formed signal recording layer made of a magnetic material. These pits are formed so that the minimum pitch is 0.6 μm. A servo clock signal is written in each of the zones A, B, C and D.

In this magneto-optical disk 102, pits corresponding to the above information signals are formed in each of the zones A, B, C and D with a substantially constant linear density. That is, the information signals recorded in the zones A, B, C and D are recorded at substantially the same linear recording density. Further, since the magneto-optical disk 102 is rotationally driven by the spindle motor 3 at a constant angular velocity, the frequency of the digital signal corresponding to the pit in each zone A, B, C, D becomes higher in the outer zone and becomes higher in the inner zone. The lower the zone, the lower the zone. The servo clock signal has a constant clock frequency f over the inner and outer circumferences of the signal recording area.
It is recorded that reading is performed by ₁ .

In this magneto-optical disk recording / reproducing apparatus, the servo clock signal is supplied to each zone A, B, C, D.
Is multiplied by a frequency conversion ratio a corresponding to and used as a channel clock signal having a frequency of af ₁ . The frequency conversion ratio a is smaller in the zone on the inner circumference side and larger in the zone on the outer circumference side. That is, the frequency af ₁ of the channel clock signal is lower toward the inner circumference side zone,
The outer zones are made higher, and the zones A, B,
It is proportional to the frequency of the digital signal written and read in C and D. In this magneto-optical disc recording / reproducing apparatus, since the frequency af ₁ of the channel clock signal is proportional to the frequency of the digital signal, the digital signal can be written in and read from the magneto-optical disc 102 based on this channel clock signal. The magneto-optical disk 102 can record an information signal of about 300 MB (megabyte) at the maximum.

In this magneto-optical disk recording / reproducing apparatus, the signal recording area of the magneto-optical disk 102 is divided into a plurality of zones to form the pits at a substantially constant linear density.
Further, since the disk 102 is rotated at a constant angular velocity, the recording density of the information signal recorded on the magneto-optical disk 102 can be improved without increasing the size of the apparatus itself and complicating it. You can That is, when the pits are formed with a constant linear density so that the frequency of the digital signal read from the magneto-optical disk 102 becomes constant over the inner and outer circumferences, the magneto-optical disk 102 is used as the objective lens 55. Since it is necessary to rotationally drive so that the constant linear velocity is achieved in the part where
This complicates the structure of the disk rotation drive mechanism for rotating the magneto-optical disk 102, particularly the spindle motor and the motor control circuit for controlling the spindle motor. When rotating the magneto-optical disk 102 at a constant angular velocity so that the frequency of the digital signal read from the magneto-optical disk 102 becomes constant over the inner and outer circumferences, as shown in FIG. Since it is necessary to reduce the linear density of pits on the outer peripheral side, the recording density of information signals on the magneto-optical disk 102 cannot be improved.

In the magneto-optical disk recording / reproducing apparatus according to the present invention, the so-called partial response NRZ is adopted as the signal modulation method of the information signal recorded on the magneto-optical disk 102 to record on the magneto-optical disk 102. The amount of information signal that can be made possible is about 1.2 times, that is, about 360 MB. Further, in this magneto-optical disk recording / reproducing apparatus, the semiconductor laser 50
By setting the wavelength of the light beam emitted by the optical disc to 680 nm, the amount of information signals that can be recorded on the magneto-optical disk 102 can be increased by about 1.316 to about 470 MB.

Further, in the optical pickup device in the magneto-optical disk recording / reproducing apparatus according to the present invention, the objective is the periodic movement of the recording track in the radial direction of the magneto-optical disk 102 due to the eccentricity accompanying the rotational driving of the magneto-optical disk 102. The so-called tracking servo that follows the light beam transmitted from the lens 55 is performed by deflecting the light beam incident on the objective lens 55 by the galvano mirror 53. However, this tracking servo is supported by the pickup guide shafts 63 and 64 of the lens bobbin block 60, or only the objective lens 55 is supported via the objective lens driving device, and the tracking servo is performed with respect to the lens bobbin block 60. It can also be performed by moving and displacing 102 in the radial direction.

By the way, the magneto-optical disk recording / reproducing apparatus according to the present invention is constructed such that the magneto-optical disk alone is mounted on the disk table 4 constituting the disk rotation drive mechanism without using the disk cartridge. Therefore, it is not necessary to provide a space for housing the disc cartridge in the outer casing 1. Therefore, the magneto-optical disk housed in the outer casing 1 has a rectangular outer casing 1.
The size can be increased to a size having a diameter substantially inscribed in.

As described above, the outer casing 1 has the width Q of 10
When formed to have a size of 1.6 mm, a depth P of 145 mm and a height H of 25.4 mm, the magneto-optical disk 202 has a diameter R ₂ of 95 mm as shown in FIG. The size can be increased. Magneto-optical disk 20 having a diameter R ₂ of 95 mm
In No. 2, the signal recording area is formed over the range from the position of the inner diameter of 40 mm to the position of the outer diameter of 90 mm. By increasing the size of the magneto-optical disk 202 used in this way, the signal recording area can be increased, and the capacity of the recorded information signal can be increased.
In this case, the outer diameter of the disk rotation drive mechanism to which the magneto-optical disk 202 is integrally attached is 95 mm, which corresponds to the outer diameter of the magneto-optical disk 202.

[0059]

As described above, in the magneto-optical disk recording / reproducing according to the present invention, the magneto-optical disk, the disk rotation driving means, the optical head means, the external magnetic field generating means and the control means are
Width is less than 101.6mm and depth is 145
Since it is housed in an outer casing with a height of 25.4 mm or less and no more than mm, it is possible to record a large amount of information signal even with a small diameter in a small outer casing. And eggplant

In particular, the magneto-optical disk housed in the outer casing is made of a light-transmissive disk substrate having a thickness of 1.2 mm or less and a diameter of 95 mm or less. Further, the recording capacity is further increased because it is divided into a plurality of signal recording areas whose linear recording densities are substantially equal to each other.

Further, since the optical head means is composed of the fixed optical system part and the movable optical system part, the means for driving the optical head means can be miniaturized and the apparatus itself can be further miniaturized. You can

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing a schematic configuration of a magneto-optical disk recording / reproducing apparatus according to the present invention.

FIG. 2 is a schematic perspective view showing the inside of the magneto-optical disc recording / reproducing apparatus as seen through.

FIG. 3 is an external perspective view showing a schematic configuration of the magneto-optical disc recording / reproducing apparatus.

FIG. 4 is an enlarged plan view showing a part of an optical pickup device constituting the magneto-optical disk recording / reproducing device according to the present invention in a cutaway manner.

FIG. 5 is a side view of an essential part showing a part of the magneto-optical disk recording / reproducing device in a cutaway manner.

FIG. 6 is a cross-sectional view showing a magneto-optical disk that constitutes the magneto-optical disk recording / reproducing apparatus according to the present invention.

FIG. 7 is a plan view schematically showing a signal recording area of the magneto-optical disk.

FIG. 8 is a partial side view schematically showing a state in which an information signal is recorded in a signal recording area of the magneto-optical disc.

FIG. 9 is a partial side view schematically showing another example of a state in which an information signal is recorded in the signal recording area of the magneto-optical disc.

FIG. 10 is a block diagram showing a control device that constitutes the magneto-optical disk recording / reproducing device according to the present invention.

FIG. 11 is an external perspective view showing another example of the magneto-optical disk recording / reproducing apparatus according to the present invention.

[Explanation of symbols]

 1 Outer Housing 2 Chassis 3 Spindle Motor 4 Disk Table 17 Objective Lens Driving Section 18 Optical Block Section 50 Semiconductor Laser 60 Lens Bobbin Block 63, 64 Guide Shaft 65 Feed Motor 66 Magnetic Head Device 70 Control Unit 102 Magneto-Optical Disc

Claims (5)

[Claims] 1. The thickness is 1.2 mm or less and the diameter is 9 mm.
A signal recording layer is formed on one main surface side of a disc substrate having a light transmittance of 5 mm or less and divided into a plurality of signal recording areas having substantially equal linear recording densities from the inner circumference to the outer circumference. A magneto-optical disk, a disk rotation driving means for mounting the magneto-optical disk and rotating the magneto-optical disk at a constant angular velocity, an optical head means for irradiating the magneto-optical disk with a light beam, and the magneto-optical disk. An external magnetic field generating means, which is disposed so as to face the optical head means with the optical disk interposed therebetween and applies a vertical magnetic field to the magneto-optical disk when an information signal is recorded on the magneto-optical disk, the disk rotation driving means, and the optical head. Means and a control means for controlling the external magnetic field generating means, a width of 101.6 mm or less and a depth of 145
The height is less than 2 mm and the height is less than 25.4 mm, and the magneto-optical disk, the disk rotation driving means, the optical head means, the external magnetic field generating means and the outer housing for housing the control means are provided. Magneto-optical disk recording / reproducing device. 2. The optical head means includes at least a fixed optical system section having a light source, a light detection means, and an optical element for detecting a focus error, and a magneto-optical disk for the fixed optical system. A movable optical system portion that is movable in the radial direction and that includes an objective lens that focuses the light beam from the light source on the signal recording area of the magneto-optical disc, and the movable optical system portion that includes the movable optical system portion of the magneto-optical disc. 2. A magneto-optical disk recording / reproducing apparatus according to claim 1, further comprising a feeding means for feeding operation in a radial direction. 3. The feeding means has a pair of parallel guide portions for guiding the movable optical system portion in the system direction of the magneto-optical disk, and the optical head means extends along the pair of parallel guide portions. 3. The magneto-optical disk drive device according to claim 2, further comprising means for movably supporting the movable optical system section. 4. The magneto-optical disk recording / reproducing apparatus according to claim 2, wherein the objective lens is an aspherical lens having a numerical aperture of 0.55 or less. 5. The magneto-optical disk has a storage capacity of 30.
The magneto-optical disk recording / reproducing apparatus according to claim 1, which is 0 megabytes or more.